Audio problem: Just after Homer says "About 3 Weeks" in reply to Bart's question about how long Grandpa lived with them, the family all start laughing. However, the second time Homer laughs, his mouth doesn't move.

This is a mistake for the introduction for the later episodes. When Homer screams, he turns round. You see this in a wide shot. There are no boxes to the right of the door in the garage. However, two just appear out of thin air when he runs through the garage.